When you hold the broker license and run the brokerage, the IRS stops seeing you as someone who earns commissions and starts seeing you as a business that collects them. Every closing check that lands in the brokerage account is gross receipts, even the portion you immediately pay out to the agent who worked the deal.
Commission income lands on Schedule C, not a W-2
A broker operating as a sole proprietor or single-member LLC reports all brokerage income on Schedule C of Form 1040. That includes your own deal commissions, your side of every agent split, desk fees you charge agents, and referral fees. Nothing is withheld along the way: the title company or the cooperating brokerage pays you gross, and taxes are entirely your problem to calculate and send in.
From that gross number you deduct the business: splits paid out to agents, office rent, E&O insurance, MLS and board dues, marketing, transaction coordination, and staff wages. What remains, often called the company dollar in brokerage accounting, is your taxable net profit.
The 15.3% self-employment layer on company dollar
Net profit from Schedule C picks up self-employment tax on Schedule SE: 15.3%, covering Social Security and Medicare, on top of ordinary federal income tax and any state tax. It applies once net earnings pass $400 for the year. Because brokers stack a personal production income stream on top of override income from their agents, net profit can climb fast, and the combined federal bill on a strong year regularly lands between 25% and 40% of company dollar depending on bracket.
That is why the deduction side matters so much. Every dollar of legitimate expense, from the office lease to agent recruiting costs, avoids both income tax and the 15.3%.
Where entity choice changes the math for a brokerage
Many broker owners do not stay on Schedule C forever. An LLC taxed as an S corporation lets you pay yourself a reasonable W-2 salary and take remaining profit as distributions that skip self-employment tax. A brokerage with partners files Form 1065 and issues each partner a Schedule K-1. The underlying income is still ordinary and still taxed at your personal rates; what changes is how much of it is exposed to the 15.3% and how cleanly the brokerage's books separate from your personal return.
Whatever the structure, brokers pay as they go. The IRS expects quarterly estimated payments on Form 1040-ES (April 15, June 15, September 15, January 15), and a brokerage that waits until filing season to think about taxes usually meets penalties before it meets its refund. Treat the brokerage like the business it is: track gross commission in, splits out, and expenses monthly, and the return becomes arithmetic instead of archaeology.